Triplex trim mower with laterally adjustable cutting units

ABSTRACT

A triplex trim mower ( 100 ) including a vehicle ( 102 ) having two front drive wheels ( 104 ) and one rear steerable wheel ( 106 ). Mounted generally forward of the front wheels ( 104 ) are two reel-type cutting units ( 108   a ) laterally offset about the longitudinal axis ( 110 ) of the vehicle ( 102 ). Mounted between the front and rear wheels and substantially centered between the forward cutting units ( 108   a ) is a rear reel-type cutting unit ( 108   b ). A lateral support frame ( 137 ) is incorporated into the main frame of traction vehicle ( 102 ). The cutting units ( 108 ) are supported by a lateral carrier frame ( 144 ) which is slidably engaged to lateral support frame ( 137 ) such that carrier frame ( 144 ) can move laterally relative to support frame ( 137 ). A hydraulic cylinder ( 158 ) permits carrier frame ( 144 ) to be laterally displaced under operator command. Second and third hydraulic cylinders ( 131 ) permit cutting units ( 108 ) to be moved between a transport position and an operating position. A single joystick ( 118 ) permits the operator to control all aspects of cutting unit position including transport or operating position and lateral offset position. The reel-type cutting units ( 108   a  and  108   b ) can be replaced with rotary cutting units ( 208  and  208   b ).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.08/969,799, filed Nov. 13, 1997, now U.S. Pat. No. 6,032,441.

TECHNICAL FIELD

The present invention relates generally to turf maintenance equipment,and more particularly to a triplex trim mower with laterally adjustablecutting units.

BACKGROUND OF THE INVENTION

Many types of power turf mowing equipment are known. Such equipment cangenerally be classified by the type of cutting unit the particular moweremploys. A rotary cutting unit includes one or more rigid steel bladesrotated about a vertical axis within a housing or “cutting deck.” Theblades cut the grass at a predetermined height above the ground. On theother hand, a reel cutting unit includes a frame within which is mounteda rotating reel having a plurality of arcuate blades, the reel rotatingabout a generally horizontal axis. The rotating reel blades pass inclose proximity to a bedknife which spans the cutting unit frameparallel to the reel axis. Grass is sheared as it passes between thereel blade and bedknife. While rotary cutting units are suitable formany purposes, it is generally perceived that reel cutting units providea more precise cut. The present invention relates to reel-type mowersand the remainder of this discussion will focus accordingly.

Power turf mowing equipment can also be categorized based on the methodused to propel the cutting units. Generally, there are walk-behind,riding, and towed turf mowers. The present invention relates primarilyto riding turf mowers and specifically, those riding turf mowers withthree reel-type cutting units, generally referred to as triplex mowers.

Triplex mowers typically include a traction vehicle supported by aplurality of wheels, including one or more traction wheels; a primemover supported by the vehicle frame and connected through atransmission to the traction wheel(s); and three cutting units poweredby the prime mover, two units mounted generally ahead of the frontwheel(s) and laterally offset about the longitudinal or fore-and-aftaxis of the vehicle, and one unit mounted generally between the frontand rear wheels and centered about the vehicle longitudinal axis.Typically, the two forward cutting units of a triplex mower aresymmetrically offset about the longitudinal axis of the tractionvehicle, leaving an uncut section therebetween during operation. Beingcentered about the longitudinal axis of the vehicle, the rear cuttingunit then spans the uncut section and overlaps the mowed path of bothforward units. Consistent mowing across the full span of the cuttingunits is thus obtained. When not cutting, the mower typically has theability to raise the cutting units to a “transport” position.

Triplex turf mowers can further be differentiated by the particularmowing task they perform. A greens mower is generally a small,maneuverable mower with high-precision cutting units suitable formaintaining golf greens. These mowers often include a grass collectionsystem to collect clippings. A second type of turf mower is the fairwaymower. Reel-type fairway mowers are generally larger that greens mowersand often include five or more cutting units (e.g., “5-plex” mowers) fora wider mowed path. Finally, a trim mower is similar in size to thegreens mower but is designed specifically to mow around tees and turfboundaries, e.g., around greens, sandtraps, and water.

The trim mower differs from the greens mower in other respects as well.For example, the greens mower is designed to provide a high precisioncut on relatively flat, smooth turf. The trim mower, however, whileslightly sacrificing quality of cut, can mow irregular turf such asintermediate roughs and inclines. The tires of the two mowers alsodiffer. In order to traverse irregular turf, the tires of the trim mowermust have adequate tread to ensure traction. The tires of the greensmower, on the other hand, usually have minimal tread in order to reducepossible damage to the green. Additionally, because of the more precisecut required of the greens mower, it typically operates at lower vehiclevelocities than the trim mower. Thus, the trim mower and the greensmower, while similar in some respects, are each designed to addressseparate turf maintenance needs.

The present invention, as previously stated, is directed specifically totriplex trim mowers. Like the greens mower, the trim mower must behighly maneuverable to permit operation around irregular boundaries.Additionally, the overall cutting width of the trim mower must remainsufficiently narrow to permit passage between course impediments, e.g.,landscaping and trees. As such, the front cutting units typicallyprovide minimal lateral extension beyond the outer edge of each frontwheel. While this configuration results in a nimble mower, there is asignificant drawback. A historical problem with conventional trim mowersis that the operator must necessarily place the front wheel close to theboundary to be mowed. Typically, these boundaries can have sharpdrop-offs (i.e., lower elevation) from the turf being mowed. Forexample, the boundaries of a sand trap are generally several inchesbelow turf level. When mowing around such areas, the operator mustensure that the front wheel of the mower remains on the turf and doesnot drop over the boundary. That is, the operator must maintain a safedistance between the wheels and the boundary being mowed. Dropping awheel, in addition to damaging the cutting units, can negatively affectthe stability of the mower and possibly endanger the operator.Accordingly, at the completion of the mowing operation, it is oftennecessary to perform a subsequent trimming operation with either a handmower or flexible line trimmer. This additional clean-up step isinconvenient and time-consuming.

These problems have been addressed in the past by merely increasing thewidth of the cutting units, thereby increasing the lateral extensionbeyond the front wheels. Unfortunately, longer cutting units make themower wider and less maneuverable. Additionally, the ground-followingcapability of the cutting unit diminishes with increased length,resulting in uneven cutting. As such, increased cutting unit width hasnot resolved the issues regarding effective trim mower operation.

Thus, a mower providing increased lateral extension of the cutting unitswithout sacrificing mower maneuverability or performance is highlydesirable. The Applicants are aware of several devices that have soughtto address this need in the context of non-trim mowers by providinglaterally adjustable or laterally offset cutting units. As explained,though, these devices do not adequately address the unique requirementsof the trim mower.

There are a number of non-trim mowers designed to laterally extend andretract the cutting unit(s) relative to the support vehicle. Many ofthese mowers utilize a single, side-mounted cutting unit. Thisconfiguration substantially increases mower width and therefore limitsmaneuverability, an undesirable consequence for a trim mower. Forexample, U.S. Pat. No. 2,882,978 issued to Smith et al, discloses aselectably slidable, laterally offset mower for trimming beneathoverhanging obstacles such as low tree branches. U.S. Pat. No.4,873,818, issued to Turner, is directed to a similar mower thatprovides increased offset capability.

Conventional riding mowers with singular, rotary cutting decks that maybe laterally displaced relative to the vehicle are also known. Forinstance, U.S. Pat. No. 4,893,456 issued to Wallace, and U.S. Pat. No.5,483,789 issued to Gummerson, show a single cutting deck that can belaterally displaced from a conventional centered position to a laterallyextended position. However, neither of these inventions describes amethod for laterally moving a plurality of separate reel-type cuttingunits in the context of a triplex trim mower.

Applicants are also aware of towed cutting units capable of lateraldisplacement relative to the vehicle. U.S. Pat. No. 3,090,184 to Hadekshows a towed gang mower wherein the central mowers move laterallyrelative to the rest of the gang. In U.S. Pat. No. 3,893,283 to Dandl, atowed gang of two cutting units is described wherein a trailing unit ispivotally mounted to a forward unit. The trailing unit may beselectively positioned about the latter to laterally displace the mowedpath. However, the forward cutting unit remains fixed relative to thevehicle at all times.

Lastly, U.S. Pat. No. 4,866,917, issued to Phillips et al, discloses atriplex greens mower with a fixed offset reel arrangement. Thisparticular mower is directed to the unique requirements of greensmowers. Typical greens maintenance involves an outer perimeter cutfollowed or preceded by parallel back-and-forth cuts over the remainderof the green. In the past, the perimeter cut required the mower totraverse roughly the same cutting path each time. As a result, somebelieve that compaction of the green may have occurred due to therepeated passing of the vehicle wheels over the same path. By providingan offset reel configuration, the Phillips invention allegedly allowsthe operator to reduce turf compaction by merely alternating thedirection of the subsequent perimeter cut. Since the cut path islaterally offset from the wheel base, switching directions causes thewheels to follow a different path for the same cut. While potentiallycommendable in eliminating compaction of greens, the fixed relationshipof the reels in the Phillips invention is not necessarily beneficial totrim mowers. For example, such a mower would be forced to traverse trimboundaries in a uniform direction to take advantage of the fixed offsetcutting units. Due to the irregular nature and occurrence ofobstructions encountered during trim mower operation, a fixed offsetreel arrangement serves little if any benefit.

Thus, there is an unmet need for an improved mower that incorporates thesuperior cutting performance and maneuverability of the triplex trimmower with the ability to operate safely and effectively near trimboundaries. The triplex mower of the present invention addresses thisproblem.

SUMMARY OF THE INVENTION

Accordingly, one embodiment of the triplex trim mower of the presentinvention includes a traction vehicle; a lateral support frame attachedto the undercarriage of the vehicle; three reel-type cutting units; alateral carrier assembly supporting the cutting units and slidablyengaged to the support frame, wherein the lateral carrier assembly canbe laterally displaced relative to the support frame; means forselectively positioning the carrier assembly laterally along the supportframe; and means for restraining the carrier assembly relative to thesupport frame.

Preferably, the lateral carrier assembly is a single lateral carrierframe supporting all three cutting units.

In the preferred embodiment, the positioning means and the restrainingmeans are embodied in a single hydraulic cylinder.

The invention can also include a means for lifting the cutting unit(s)from an operating position to a transport position. In the preferredembodiment, the lifting means comprises a second hydraulic cylinder forlifting the front cutting units and a third hydraulic cylinder forlifting the rear cutting unit.

In still a further preferred embodiment, the hydraulic cylinders used tolift and laterally displace the cutting units are both controlled from asingle joystick positioned near the operator.

Additional features and aspects of the present invention are describedin detail below with reference to the Drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described with reference to the Drawings,wherein:

FIG. 1 is a perspective view of the triplex trim mower according to theinvention;

FIG. 1A is an enlarged perspective view of the joystick control lever ofthe trim mower of FIG. 1;

FIG. 2 is an enlarged perspective view of the cutting unit carriersystem of the trim mower in FIG. 1;

FIG. 3 is an enlarged perspective view of a portion of the carriersystem of FIG. 2;

FIG. 4 is a top plan view of the carrier system of FIG. 2 showing thecarrier frame in the centered position;

FIG. 4A is a top plan view of the scissors linkage of the carrier systemof FIG. 4;

FIG. 5 is a top plan view of the carrier system of FIG. 2 showing thecarrier frame in the leftmost position;

FIG. 5A is a top plan view of the scissors linkage of the carrier systemof FIG. 5.

FIG. 6 is a top plan view of the carrier system of FIG. 2 showing thecarrier frame in the rightmost position;

FIG. 6A is a top plan view of the scissors linkage of the carrier systemof FIG. 6;

FIG. 7 is an enlarged perspective view of a portion of the carriersystem of FIG. 2;

FIG. 8 is an enlarged partial section view of a portion of the carriersystem of FIG. 2;

FIG. 9 is a front elevational view of the mower of FIG. 1 with thecutting units laterally displaced for mowing around a water boundary;

FIG. 10 is a front elevational view of the mower of FIG. 1 with thecutting units laterally displaced for inclined cutting.

FIG. 11 is a perspective view of a second embodiment of a triplex trimmower according to the invention;

FIG. 12 is a perspective view of a rotary cutting unit used on the mowerof FIG. 11;

FIG. 13 is a front elevational view of the rotary cutting unit shown inFIG. 12;

FIG. 14 is a side elevational view of the rotary cutting unit shown inFIG. 12;

FIG. 15 is a top plan view of the rotary cutting unit shown in FIG. 12;

FIG. 16 is a front elevational view of a portion of the cutting unitshown in FIG. 12, namely a front elevational view of the cutting deckwith the roller frame having been detached from the cutting deck suchthat the cutting deck is illustrated by itself;

FIG. 17 is a top plan view of the cutting deck portion, shown in FIG.16, of the cutting unit;

FIG. 18 is a bottom plan view of the cutting deck portion, shown in FIG.16, of the cutting unit; and

FIG. 19 is a side elevational view of the cutting deck portion, shown inFIG. 16, of the cutting unit, with the baffles having been removed fromthis view to better illustrate one of the front corner cut-outs of thecutting deck.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference to the Drawings, wherein like reference numeralsdesignate like parts and assemblies throughout the several views, FIG. 1shows a perspective view of a preferred turf maintenance machine 100according to the invention. Machine 100 includes a traction vehicle 102including a main frame 137 (shown in FIG. 2) supported by a pair offront drive wheels 104 appropriately coupled through a transmission (notshown) to a prime mover (also not shown). A rear steerable wheel 106,which may or may not be powered, supports the rearward end of vehicle102.

In its most preferred form, turf maintenance machine 100 is a highprecision riding mower specifically intended for use as a triplex trimmower. In this embodiment, there are two front, reel-type cutting units108 a spaced along a line generally perpendicular to a fore-and-aft orlongitudinal axis 110 of vehicle 102 and directly in front of drivewheels 104; and a single rear, reel-type cutting unit 108 b roughlycentered between front cutting units 108 a and also arranged along aline which is generally perpendicular to longitudinal axis 110 ofvehicle 102.

Referring generally to the Drawings, parts and assemblies performing thesame function with respect to the front and rear cutting units aresubstantially identical and, as such, referred to with like referencenumerals. Thus, the “a” and “b” suffixes will not hereafter be usedunless necessary to clarify the invention.

In the embodiment shown in FIG. 1, an operator sits in an operator seat114 and steers traction vehicle 102 by means of steering wheel 116which, when turned, causes rear wheel 106 to pivot about a verticalaxis, thereby steering the vehicle. Various levers and pedals permit theoperator to control engine speed, brakes, etc. In particular, a joystick118 provides positional control of cutting units 108. The prime moverpowers one or more hydraulic pumps which provide(s) hydraulic fluid tothe wheel and cutting unit motors, under control of variousoperator-controlled valves.

Although the particular construction of the reel units 108 is, for themost part, not central to the invention, the basic components will bedescribed. Referring particularly to FIG. 4, a pair of generallyrectangular side plates 120 are located at opposite ends of reel unit108. Plates 120 are spanned at the top by a steel cross tube 122 and atthe bottom by a rear roller (not shown) and a front roller 126 (shown inFIG. 1). The front roller can be a so-called “wiehle” roller, having aseries of circumferential grooves across its entire width. Also spanningthe side plates 120 is a horizontally centrally mounted rotatable reel128 which is coupled to a hydraulic motor 130.

Cutting unit 108 also includes several shields (not shown) which helpconfine and direct the grass clippings. These shields are generallyconcentric to and offset from cutting reel 128. The standing grassblades are sheared off toward the bottom of the reel, at a stationarybedknife (not shown).

Per FIG. 4, each cutting unit 108 operably attaches to main frame 137with a lift arm 134. Referring generally to FIGS. 2 and 3, each lift arm134, at its “inboard” end, pivotally attaches to a carrier assembly 144which is, in turn, operably connected to main frame 137. In thepreferred embodiment, the carrier assembly comprises a single carrierframe 144 (described in detail below) supporting all three cutting unitsbut a carrier assembly comprising two or more carrier frames is alsopossible within the scope of the present invention. At its opposite or“outboard” end, lift arm 134 pivotally attaches to cutting unit 108. Ahorizontal axis carrier pivot 132 permits each lift arm 134 to rotate ina generally vertical plane about carrier frame 144. A stem pivot 136,having an axis substantially parallel to pivot 132, allows each cuttingunit 108 to pivot about lift arm 134. Thus, each cutting unit 108 mayeffectively pivot about joints 132 and 136. This range of freedomensures that cutting units 108 maintain optimal ground contact acrosstheir width regardless of lateral variations in ground elevation.

Still referring to FIGS. 2 and 3, the operator may selectively raisecutting units 108 from a lowered or “operating” position to an elevatedor “transport” position when the cutting units are not in use. In thepreferred embodiment, this is accomplished with two hydraulic liftcylinders 131 a and 131 b. Situated between the two front lift arms,cylinder 131 a is pivotally attached at its rod (actual rod attachmentstructure omitted in FIG. 3 for clarity) and at its cylinder to opposingbellcranks 133 a located on lift arms 134 a. When the operator commandsjoystick 118 to raise the cutting units, cylinder 131 a extends, drivingbellcranks 133 a apart and thus, forcing lift arms 134 a to rotate aboutpivot joints 132 a. This motion raises the front cutting units from theoperating to the transport position.

Rear cylinder 131 b raises the single rear cutting unit 108 b. Sinceonly one lift arm is provided, cylinder 131 b has its cylinder endoperably mounted to carrier frame 144 and its rod end pivotally attachedto a bellcrank 133 b on rear lift arm 134 b. Cylinder 134 b operates inparallel with cylinder 134 a such that the operator must give only onecommand to raise both the forward and rear cutting units. In thepreferred embodiment, the rear cutting unit can be raised to its maximumtransport position without interfering with vehicle 102.

Having described the cutting units, attention will now be focused oncarrier frame 144 and its related structure.

Carrier Frame

Referring to the Drawings and particularly to FIGS. 2 and 3, the mainframe of vehicle 102 includes a support frame 137. The support framecomprises: left frame side plate 138 and a right frame side plate 140located immediately inboard of left and right front wheels 104respectively; and a pair of frame members 142 spanning side plates 138and 140. Front frame member 142 a is circular in cross section and rearframe member 142 b is square in cross section (however, the exact shapeof these members is not critical). Slidably engaged to frame members 142is carrier frame 144. Referring to FIGS. 4 and 6, a scissors frame 146operably attaches to both carrier frame 144 and left side plate 138.Scissors frame 146 includes a first link 148 and a second link 150.First link 148 pivots about a frame pivot joint 152 proximal to sideplate 138. Second link 150 pivots about a carrier pivot joint 154 atcarrier frame 144. A scissors pivot joint 156 connects first link 148 tosecond link 150. Pivot joints 152, 154, and 156 each permit pivotingabout a substantially vertical axis such that the scissors linkage moveswithin a plane which is parallel to the ground. Conventionalbearings/bushings can be used to reduce friction at the pivot joints.Thus, a carrier system 141 comprising carrier frame 144, scissors frame146 and support frame 137 is positioned on the front underside ofvehicle 102.

Still referring to FIGS. 4 and 6, a double-acting hydraulic carriercylinder 158 has its base end pivotally connected at pivot joint 152 andhas its rod end pivotally attached to a rod pivot joint 160 located onlink 150. By extending and retracting carrier cylinder 158, scissorsframe 146 is displaced. Displacement of scissors frame 146 causeslateral motion of carrier frame 144 along frame tubes 142. That is, byextending and retracting carrier cylinder 158, the carrier frame andattached cutting units 108 are laterally displaced. In the preferredembodiment, carrier frame 144 (and the attached cutting units) can beselectively displaced 12 inches to either side of center. Table I belowshows the preferred nominal dimensions and angles of the scissors framein three different positions (centered, leftmost, and rightmost).

TABLE I Dimensional Data, See FIGS. 4A, 5A, 6A Item Value 148 (length)15.95 inches 150 (length) 16.08 inches X (angle)  53° Y (angle)  8° Z(angle) 110°

FIG. 5 shows a top plan view of carrier system 141. Carrier frame 144comprises a forward beam 162, a rear beam 164, a rear beam extension165, and two cylindrical struts 166 spanning forward beam 162 and rearbeam 164. Forward beam 162 supports the forward lift arms 134 a, cuttingunits 108 a, and accompanying hydraulics components while rear beam 164supports rear lift arm 134 b, cutting unit 108 b, beam extension 165,and accompanying hydraulic components including a hydraulic bulkhead 168(attached at the end of beam extension 165) used to route all carrierframe hydraulics.

Referring generally to FIG. 3, a pair of bearings 170 slidably engagedto frame member 142 a is rigidly attached to the lower side of forwardbeam 162. In the preferred embodiment, bearings 170 are polyphenylenesulfide (also known by the trade name “RYTON”) blocks with a clearancebore for frame member 142 a. However, other bearing materials may alsobe used. Each bearing block is split and the two halves are then boltedto forward beam 162. Bearings 170 align carrier frame 144 to framemember 142 a.

Referring to FIGS. 3, 7, and 8, a single, “U-shaped” rear slide support172 encompassing frame member 142 b is rigidly attached to the lowerside of rear beam 164. Located intermediate to rear beam 164 and framemember 142 b is a plastic slide 174. An identical slide is locatedbetween the lower side of frame member 142 b and the inside bottom faceof U-shaped bracket 172 as shown in FIGS. 7 and 8. Preferably, theplastic slides are “UHMW” polyethylene but other materials may also beacceptable. U-shaped bracket 172 and plastic slides 174 provide verticalsupport to the carrier frame but do not restrain carrier frame 144 inthe fore-aft direction. Thus, bracket 172 and slides 174 allow forslight misalignment between frame members 142 yet still provide adequatesupport for carrier frame 144. The combination of low-friction bearings170 and plastic slides 174 allows carrier frame 144 to slide laterallywith limited resistance, even when bearing the full weight of thecutting units.

Carrier cylinder 158, lift cylinders 131, and hydraulic reel motors 130are operably connected to a hydraulic pump (not shown) on tractionvehicle 102. Hoses (not shown) for all hydraulic equipment on carrierframe 144 connect at a common bulkhead 168. Hose lengths are sized toallow unrestricted movement of carrier frame 144 and cutting units 108.

As described above, cutting units 108 can be positioned both laterallyto traction vehicle 102 and vertically between the transport andoperating positions. Either motion is controlled by the operator viajoystick 118 shown in FIGS. 1 and 1A. That is, manipulation of joystick118 permits the operator to laterally displace cutting units 108 toeither the left or right as well as to the transport or operatingpositions. The joystick is operably connected to a hydraulic valve (notshown) having a first and a second spool. The first spool controlshydraulic flow to carrier cylinder 158 while the second spool controlshydraulic flow to cylinders 131. Each spool is biased to a centeredposition. In its centered position, each spool effectively blocks allhydraulic flow to and from its respective cylinder(s). This effectively“locks” the cylinder(s) in place. A mechanical linkage (not shown)operably connects each spool valve to joystick 118.

Joystick 118 is biased to its centered position by the biasing force ofeach spool valve. Thus, with no operator input, joystick 118 is centered(as shown in FIG. 1A) and each spool is in its centered position(thereby blocking flow to cylinders 158 and 131). The other positions ofjoystick 118 and the resultant spool actions are described below.

Operation

With the carrier frame in its centered or initial position as shown inFIG. 4, machine 100 is configured as a conventional triplex trim mower.However, unlike conventional mowers, upon approaching a trim boundary(e.g., water as shown in FIG. 9), the operator may laterally extendcutting units 108 to mow a path laterally offset from vehicle 102. Forexample, to extend the cutting units to the right, the operatorselectively commands joystick 118 to a “right” position (depicted asposition A in FIG. 1A). When this occurs, the first spool directshydraulic flow to extend carrier cylinder 158. As the carrier cylinderextends, it forces scissors frame 146 to “open” (i.e., the scissorsframe spreads) as shown in FIG. 6. As the scissors frame opens, carrierframe 144 (and thus, the attached cutting units) moves to the rightalong frame members 142. The operator may stop the travel of carrierframe 144 at any intermediate position by simply releasing joystick 118.Upon release of the joystick, the first spool is biased to its centeredposition, once again locking cylinder 158 in place. The biasing force ofthe first spool also forces joystick 118 to return to its centeredposition.

When the operator desires to laterally offset the cutting units to theleft of vehicle 102, joystick 118 is commanded to a “left” position(depicted as position B in FIG. 1A). This causes the first spool todirect hydraulic flow to retract carrier cylinder 158. Referring to FIG.5, retraction of the carrier cylinder causes scissors frame 146 to“close,” pulling carrier frame 144 toward the left side of tractionvehicle 102. Once again, the operator may stop the travel of the carrierframe at any intermediate position by simply releasing joystick 118. Thehydraulic flow rate to and from cylinder 158 is restricted to slow thedisplacement rate of carrier frame 144. Preferably, the flow isrestricted such that the carrier frame moves no faster than 8inches/second at a supply pressure of 1000 psi (nominal). In thepreferred embodiment, carrier cylinder 158 can laterally displacecarrier frame 144 (and thus cutting units 108)±12 inches (12 inches tothe left and 12 inches to the right), resulting in total lateraladjustability of 24 inches. Ideally, the cutting units can be laterallypositioned during the mowing operation without damage to mower 100.

At the completion of the cutting operation, cutting units 108 can beraised to their transport position for travel to the next site. This isaccomplished by selectively commanding joystick 118 to a rearward or“raise” position (depicted as position C in FIG. 1A). The mechanicallinkage then shifts the second spool so that hydraulic flow is directedto extend lift cylinders 131, forcing lift arms 134 to rotate aspreviously described. Upon releasing the joystick, the second spool isbiased to its centered position, effectively locking cutting units 108in their transport position. Upon reaching the new site, joystick 118can be commanded to a forward or “down” position (depicted as position Din FIG. 1A). The second spool then directs hydraulic flow to retractlift cylinders 131, returning cutting units 108 to their operatingposition. Placement of joystick 118 in either the C or D position has noaffect upon the first spool (i.e., the cutting units can be raisedwithout affecting their lateral position). Likewise, placement of thejoystick in either the A or B position has no effect upon the secondspool (i.e., the cutting units can be laterally displaced withoutaffecting their up or down position). Thus, joystick 118 provides asimplified control interface that permits the operator to readily adjustcutting unit position.

To control cylinder extension/retraction speeds, the preferredembodiment utilizes various orifices (not shown). But proportionalcontrol valves could be used in place of the spools to allow moreprecise operator control of cutting unit position. Similarly, electricalswitches and solenoid valves could be used in place of the presentmechanical linkage and spool valves to translate joystick command tocutting unit position. However, Applicants believe the preferredembodiment is the most practical in terms of performance and cost.

In addition to providing increased lateral offset for trimming aroundboundaries, the trim mower of the present invention offers otheradvantages. For example, when mowing inclined surfaces as shown in FIG.10, the cutting units can be laterally offset to partially shift themower's weight to the uphill side. Additionally, servicing of rearcutting unit 108 b is simplified as it can be partially extended frombeneath vehicle 102, allowing improved accessibility.

While the preferred embodiment described above utilizes a hydrauliccarrier cylinder, Applicants perceive an alternative embodiment wherecarrier frame 144 would be manually displaced. That is, scissors frame146, carrier cylinder 158, and the related hydraulics would be replacedwith a manual clamp (not shown) which would restrain carrier frame 144relative to support frame 137. This embodiment would require that theoperator stop the vehicle with the cutting units in their transportposition, manually release the clamp, manually reposition carrier frame144 along frame members 142, and re-clamp the carrier frame in its newposition. While this embodiment does not offer the dynamic adjustabilitypresent in the preferred embodiment, it does allow the cutting units tobe periodically offset as mowing needs require.

Still yet another embodiment contemplated would replace scissors frame146, carrier cylinder 158, and the corresponding hydraulics with a ballscrew actuator (not shown) spanning the undercarriage of the vehicle.Carrier frame 144 would be modified to operably connect to the screw,thus allowing dynamic lateral positioning of the cutting units. Thisscrew would be powered either by an electric motor (not shown) or by anadditional hydraulic motor (also not shown).

A second embodiment of a mower according to this invention isillustrated in FIGS. 11-19. In this second embodiment, the three reeltype cutting units 108 shown in FIGS. 1-10 are replaced by three rotarycutting units 208. The system for laterally displacing rotary cuttingunits 208 is the same as the system used to laterally displace reel typecutting units 108. Namely, all three rotary cutting units 208 can bedisplaced to one side or the other from a normal, generally centeredorientation on vehicle 102 using the same cutting unit carrier systemshown in FIG. 2. The primary difference between the first and secondembodiments of the mower according to this invention is the nature ofthe cutting units themselves, namely the use of rotary cutting units 208rather than reel type cutting units 108.

A rotary cutting unit 208 of the type which may replace one of the threereel-type cutting units 108 is shown in FIGS. 11-19 and will be morefully described hereafter. The description of this one rotary cuttingunit 208 will serve to describe the other rotary cutting units 208 asall of the cutting units are generally identical. Again, since onerotary cutting unit 208 will replace each of the reel-type cutting units108 shown in FIGS. 1-10, there will be two front rotary cutting units208 a in advance of each front wheel 104 of vehicle 102. A third, rearcutting unit 208 b will be placed beneath vehicle 102 generally betweenthe front and rear wheels of vehicle 102. The rear cutting unit 208 bwill extend between and cover the gap that exists between the frontcutting units 208 a such that all three cutting units 208 a and 208 bwill cut an unbroken swath of grass. Again, this staggered andoverlapped orientation of rotary cutting units 208 is the same as shownfor reel type cutting units 108 shown in FIGS. 1-10, except that now thecutting units are rotary cutting units.

Each rotary cutting unit 208 comprises two major components that arenormally fixed together during operation of the cutting unit, but aredetachable from one another to change the cutting height. The first ofthese components comprises a cutting deck 210 which provides a cuttingchamber 212 in which a generally horizontal cutting blade 214 iscontained. Cutting deck 210 also mounts a motive means for rotatingblade 214 in a substantially horizontal cutting plane. The other ofthese components includes a roller frame 216 that mounts various groundengaging rollers. When roller frame 216 is fixed to cutting deck 210,cutting deck 210 is self-supporting on the ground and can roll over theground by virtue of the various rollers on roller frame 216. The heightof cut of rotary cutting unit 208 can be adjusted by changing oradjusting the position of roller frame 216 relative to cutting deck 210when the two are affixed together.

Cutting deck 210 of each rotary cutting unit includes a downwardlyfacing cutting chamber 212 which is defined by a circular shroud wall220 that extends downwardly from a top wall 222. As is well known inrotary cutting decks, this wall arrangement provides a generallyenclosed cutting chamber 212 which is enclosed over the sides and topthereof but is open at the bottom thereof. A rotary cutting blade 214 iscarried inside this cutting chamber 212 and rotates in a generallyhorizontal cutting plane about a generally vertical rotational axis.Cutting blade 214 has sharpened cutting edges which cut the grass asblade 214 rotates in its cutting plane. The height of cut is determinedby how far blade 214 is positioned above the ground which is, in turn,determined by the relative position of cutting deck 210 on roller frame216.

The circular shroud wall 220 of cutting deck 210 can be generallycontinuous and unbroken so that cutting deck 210 acts as a mulchingdeck. In other words, grass clippings within cutting chamber 212 willexit the chamber only through the open bottom of cutting chamber 212.However, shroud wall 220 could be also provided with a grass dischargeopening to allow grass clippings to exit through shroud wall 220 in somedesired direction, i.e. to the side of cutting deck 210 or preferably tothe rear of cutting deck 210. Thus, whether cutting deck 210 is amulching deck or a side or rear discharge deck is not important to thisinvention.

In addition, cutting deck 210 can have other walls secured to shroudwall 220 for various purposes. For example, the front and sides ofcutting deck 210 are desirably flat to carry slotted attachment brackets224 that are adjustably mated to attachment pins 226 on roller frame216. The flat front and flat sides of cutting deck 210 are provided byother straight, flat walls 228 that are secured to the front and sidesof circular shroud wall 220. See FIG. 18. In addition, top wall 222extends rearwardly past circular shroud wall 220 to further unite andjoin the straight, flat walls 228 that are secured to the sides ofcircular shroud wall 220.

A means for rotating the cutting blade within cutting chamber 212 isprovided on cutting deck 210. This rotating means comprises anindividual electric or hydraulic motor 230. Preferably, cutting deck 210includes a series of bolt holes 232 to which a motor mounting ring 234can be bolted. When so mounted and when energized, the shaft of motor230 is suitably connected to blade 214 to rotate blade 214 in itshorizontal cutting plane. Alternatively, the blade rotating means couldcomprise a drive spindle mounted on cutting deck 210 that could be beltdriven from a power takeoff shaft or the like. However, since rotarycutting unit 208 is free to pivot and tilt during operation of the mowerto conform to the ground contours in the same manner that the reel-typecutting units 108 could pivot and tilt, the use of a belt driven spindleas the blade rotating means is not preferred due to the problemsinvolved in keeping proper tension and alignment on the belt. Theseproblems are avoided by using an electric or hydraulic motor 230 as theblade rotating means.

Shroud wall 220 of the rotary cutting deck has a cut-out 240 adjacenteach front corner of cutting deck 210. By a cut-out, it is meant thatshroud wall 220 is cut away adjacent its lower edge to expose thesharpened cutting edge of blade 214 when the tip of blade 214 travelspast cut-out 240. Referring now to FIG. 18, each cut-out 240 has anangular extent of about 45° designated by the arc labelled as x and ispositioned on the front corner of cutting deck 210 so that uncut,standing grass approaching each front corner of cutting deck 210 willencounter or pass into one of cut-outs 240. As shown in FIGS. 16 and 18,blade 214 is exposed to the uncut grass in cut-out 240. Otherwise, inthe front of cutting deck 210 between cut-outs 240, blade 214 is hiddenor enclosed by the walls which define the front of cutting deck 210.

Cutting deck 210 includes baffles 250 adjacent each of the front cornercut-outs 240 for helping guide standing, uncut grass into cut-outs 240.Each baffle 250 comprises a generally upright, triangular, first bafflesurface 252 that is widest at the innermost portion of cut-out 240 anddecreases in height towards the outside of cutting deck 210. Thisupright, triangular, first baffle surface 252 is secured to the sides ofcutting deck 210 by an upper triangular support flange 254 having anoutermost, vertical side 256 that wraps down over the outermost end ofthe triangular, first baffle surface 252. The outermost, vertical side256 of the triangular support flange 254 extends rearwardly to join withthe side walls of cutting deck 210. The outermost side 256 of thetriangular support flange 254 is beneath the level of blade 214 and ofthe bottom of the triangular, first baffle surface 252. See FIG. 16.

Thus, referring again to FIG. 16 which shows the front of cutting deck210, as standing, uncut grass engages the front of cutting deck 210, thegrass that engages the middle portion of the front of cutting deck willsimply be bent beneath the lowermost edge of the walls of the deck inthe middle portion. However, the standing, uncut grass that approacheseach side of cutting deck 210 will engage the triangular, first bafflesurface 252 adjacent each of the front cut-outs 240. This first bafflesurface 252 will tend to bend the grass smoothly down into the frontcut-out 240 where the grass can be cut without being bent to one side ofcutting deck 210, the grass being further confined by the outermost side256 of the triangular support flange 254.

When rotary cutting decks 208 are arranged in a staggered orientation asin the mower of this invention, the Applicants have noticed a streakingeffect along the lines where the rear cutting deck overlaps with thefront cutting deck. This streaking effect is especially prevalent whenvehicle 102 is turning or traversing slopes. However, when cutting decks210 are equipped with the front corner cut-outs 240 and adjacent baffles250 as described and illustrated herein, streaking occurring betweencutting decks 210 is substantially eliminated or reduced.

As noted earlier, cutting deck 210 by itself comprises only onecomponent of rotary cutting unit 208. To form a complete rotary cuttingunit 208, cutting deck 210 has to be united with a roller frame 216.Roller frame 216 and its attached rollers will now be described.

Roller frame 216 comprises a generally U-shaped arch 260 defined by afront rail 262 secured to two, rearwardly extending side rails 264. Thewidth of the U-shaped arch 260, i.e. the distance between side rails264, is wide enough to allow cutting deck 210 to be positioned withinroller frame 216. Each rail 262, 264 of the U-shaped arch has anapertured attachment flange 266 that carries a plurality of holes orapertures 268 for receiving an attachment pin 226. Each attachmentflange 266 on one of the rails overlies one of the slotted attachmentbrackets 224 on cutting deck 210 so that pin 226 can pass through aselected aperture 268 and a selected slot to affix roller frame 216 andcutting deck 210 together. The height of cutting deck 210 on rollerframe 216 can be adjusted by changing which aperture and which slotreceive attachment pin 226. This is how the height of cut of the cuttingunit is adjusted.

The U-shaped arch 260 includes a single, rotatable ground engagingroller 270 at the rear of side rails 264 behind cutting deck 210 whenroller frame 216 and cutting deck 210 are united with respect to oneanother. This single ground engaging roller 270 extends all the waybetween side rails 264 over the full width of cutting deck 210. Inaddition, two, front, ground engaging rollers 272 are used on front rail262 of arch 260 adjacent each corner of cutting deck 210. These two,front rollers 272 obviously extend over a small portion of the width ofcutting deck 210 as opposed to the full length rear roller 270. Rearroller 270 need not necessarily be a full length roller, but couldcomprise a segmented roller or two separate rollers at each rear cornerof the cutting deck including two separate rear rollers shaped like thetwo, front rollers 272.

The front ground engaging rollers 272 have a novel ovate shape with therotational axis 274 of roller 272 extending transversely relative tocutting deck 210 and being arranged horizontally. The broader basal end276 of the ovately shaped roller 272 is positioned to the interior ofcutting deck 210 and the tapered outer end 278 of the ovately shapedroller 272 is positioned to the exterior of cutting deck 210. Roller 272is rotatably arranged on front rail 262 of the U-shaped arch in anysuitable manner.

The Applicants have found that the front ground engaging rollers 272have numerous advantages. They are effective replacements for thetraditional caster wheels that are often found on the front side ofrotary cutting decks. However, front ground engaging rollers 272 aresuperior to caster wheels since they can be mounted closer to the frontwall of cutting deck 210 than caster wheels. This reduces the distancebetween blade 214 and the support provided by front rollers 272 tominimize scalping and the like. However, caster wheels could be used inplace of front rollers 272 if desired.

One possible disadvantage of using a front ground engaging roller 272 inplace of a caster wheel is the tendency of such a roller to slide on theturf during a vehicle turn, which does not happen with a caster wheelthat can freely pivot about a vertical axis. Such sliding is adisadvantage as it can mar or scuff the turf. However, the Applicantshave found that the ovate shape of the front ground engaging rollers iseffective in reducing marring or scuffing during turns. Put another way,the ovate shape of rollers 272 allows cutting deck 210 to smoothly slideover the turf during turns of vehicle 102 without marring or scuffingthe turf.

In addition to the U-shaped arch 260 that mounts the front and rearground engaging rollers 272 and 270, respectively, roller frame 216includes a yoke 290 secured to side rails 264 of the arch. This yoke290, and particularly an elongated rod 292 on the yoke, is how rotarycutting unit 208 is attached to the cutting unit carrier system shown inFIG. 2. Each rod 292 slips into one of the stem pivots 136 in the samemanner as the reel-type cutting units.

Rotary cutting units 208 as disclosed herein when used to replace thereel-type cutting units 108 shown in FIGS. 1-10 will provide anotherembodiment of a mower with laterally adjustable cutting units. Thus, theoperator by using the joystick 118, can selectively laterally displacethe three cutting units 208 a and 208 b so that the cutting swathprovided by those cutting units shifts to one side or the other. This isaccomplished even considering the fact that the cutting units 208 can berolled on the ground by their own ground engaging rollers 270 and 272and can pivot and tilt during operation of the mower to follow theground contours. Thus, the second embodiment of this invention forms aneffective trim mower like that shown in the first embodiment of theinvention.

However, rotary cutting units 208 are not limited to use in a trim mowerin which the cutting units 208 can be laterally displaced, but could beused as part of other mowers. For example, a cutting unit 208 having thedisclosed ovately shaped, front, ground engaging rollers 272 would beuseful in other applications. A cutting unit 208 with front cornercut-outs 240 would be useful in eliminating streaking between multiplecutting units even if the cutting units did not shift or were arrangedin a different staggered pattern.

In addition, various other modifications will be apparent to thoseskilled in the art. For example, the bolt holes 232 provided in cuttingdeck 210 for bolting the motor and blade combination to the deck in asingle position could be replaced with slots (not shown) that areelongated in a fore and aft direction relative to the deck. Such slotswould allow the position of blade 214 in cutting chamber 212 to beadjusted from a centered position to a non-centered position, i.e. to aposition where blade 214 is shifted either forwardly or rearwardly incutting chamber 212 to provide more clearance at the rear or in thefront of cutting chamber 212, respectively. This adjustment would bemade by sliding the bolts of the motor mounting ring either forwardly orrearwardly in the slots before the bolts are secured. Shifting themotor/blade combination towards the front allows for more efficientmulching of clippings while shifting the motor/blade combination to therear provides a much smaller mulched clipping. Thus, the use of theaforementioned slots to allow a fore and aft shifting of the motor/bladecombination is useful primarily in cutting decks in which the cuttingchamber can be enclosed to mulch the clippings.

Thus, the scope of this invention is to be limited only by the appendedclaims.

We claim:
 1. A triplex mower comprising: a) a traction vehicle supportedby at least one front wheel and at least one rear wheel; b) a lateralsupport frame operably mounted to the traction vehicle; c) a pair offront cutting units located generally ahead of the at least one frontwheel; d) a rear cutting unit located generally between the at least onefront wheel and the at least one rear wheel and positioned substantiallybetween the front cutting units, wherein the front and rear cuttingunits collectively define a cutting swath which is normally disposed ina first orientation relative to the traction vehicle; e) a lateralcarrier assembly operably connecting the front and rear cutting units tothe lateral support frame, wherein the lateral carrier assembly can movelaterally relative to the support frame; f) a positioning apparatus forpositioning the lateral carrier assembly relative to the support frameto selectively laterally displace the front and rear cutting unitsrelative to the traction vehicle to shift the cutting swath defined bythe cutting units to at least one side of the first orientation of thecutting swath, whereby the traction vehicle can be operated with thecutting swath disposed in its first orientation or in at least one otherselected orientation that is laterally displaced from the firstorientation; and g) a restraining apparatus for restraining the lateralcarrier assembly relative to the support frame.
 2. The triplex mower ofclaim 1, wherein the positioning apparatus selectively laterallydisplaces the front and rear cutting units relative to the tractionvehicle to shift the cutting swath defined by the cutting units toeither side of the first orientation of the cutting swath.
 3. Thetriplex mower of claim 1, wherein the mower is a trim mower.
 4. Thetriplex mower of claim 1, wherein the positioning apparatus and therestraining apparatus are embodied in a single powered actuator.
 5. Thetriplex mower of claim 1, wherein each cutting unit has rotatablerollers or wheels which engage the ground when the cutting unit is in acutting position to allow the cutting unit to roll over the ground whencutting.
 6. The triplex mower of claim 5, wherein the cutting unitscomprise rotary-type cutting units having a cutting blade which isrotated in a substantially horizontal cutting plane.
 7. The triplexmower of claim 5, wherein the cutting units comprise reel-type cuttingunits.
 8. A triplex mower comprising: a) a traction vehicle; b) firstand second cutting units carried on the traction vehicle with the firstand second cutting units being longitudinally aligned with one anotherbut being laterally spaced from one another to have a gap therebetween;c) a third cutting unit carried on the traction vehicle, wherein thethird cutting unit is longitudinally spaced from the first and secondcutting units and is located relative to the first and second cuttingunits to cover the gap between the first and second cutting units,wherein the cutting units collectively cut a swath as the tractionvehicle is operated; and d) a single carrier frame supporting all threecutting units on the traction vehicle, wherein the carrier frame isselectively movable laterally relative to the traction vehicle to beable to laterally adjust the position of the cutting swath relative tothe traction vehicle such that the traction vehicle can be operated withthe cutting swath in different lateral positions.
 9. The triplex mowerof claim 8, wherein the first and second cutting units are placedforwardly of the third cutting unit on the traction vehicle.
 10. Thetriplex mower of claim 8, wherein the traction vehicle has a pluralityof ground engaging wheels supporting the traction vehicle for movementover the ground, the ground engaging wheels comprising at least onefront wheel and at least one rear wheel, and wherein the first andsecond cutting units are placed forwardly of the at least one frontwheel and the third cutting unit is placed between the at least onefront wheel and the at least one rear wheel.
 11. The triplex mower ofclaim 8, further including a powered actuator carried on the tractionvehicle and connected to the carrier frame for providing powered lateralmovement of the carrier frame.
 12. The triplex mower of claim 11,further including a control carried on the traction vehicle whichcontrol is manipulable by an operator of the traction vehicle toselectively actuate the powered actuator during operation of thetraction vehicle.
 13. The triplex mower of claim 11, wherein the cuttingunits are supported by rollers or wheels for rolling over the ground.14. The triplex mower of claim 11, further including a lift and lowersystem on the carrier frame for lifting and lowering the cutting unitsrelative to the carrier frame to place the cutting units in a loweredcutting position or a raised transport position.
 15. The triplex mowerof claim 8, wherein the mower is a trim mower.
 16. A mower comprising:a) a traction vehicle; b) a plurality of cutting units carried on thetraction vehicle which cutting units collectively cut a swath of grassas the traction vehicle is operated, wherein each cutting unit isindependently connected to the traction vehicle by at least one pivot topermit each cutting unit to tilt or rock relative to the tractionvehicle independently of the other cutting units when following at leastsome changes in ground contour; and c) wherein the cutting units areselectively movable laterally relative to the traction vehicle to beable to laterally adjust the position of the cutting swath relative tothe traction vehicle such that the traction vehicle can be operated withthe cutting swath in different lateral positions.
 17. The mower of claim16, wherein the cutting units comprise: a) at least first and secondcutting units carried on the traction vehicle with the first and secondcutting units being longitudinally aligned with one another but beinglaterally spaced from one another to have a gap therebetween; and b) atleast one additional cutting unit carried on the traction vehicle whichis longitudinally spaced from the first and second cutting units and islocated relative to the first and second cutting units to cover the gapbetween the first and second cutting units.
 18. The mower of claim 16,wherein each cutting unit has rotatable rollers or wheels which engagethe ground when the cutting unit is in a cutting position to allow thecutting unit to roll over the ground when cutting.
 19. The mower ofclaim 16, wherein the cutting units comprise rotary-type cutting unitshaving a cutting blade which is rotated in a substantially horizontalcutting plane.
 20. The mower of claim 16, wherein the cutting unitscomprise reel-type cutting units.
 21. The mower of claim 16, wherein theat least one pivot for each cutting unit is substantially horizontal andextends longitudinally relative to the traction vehicle substantiallyparallel to a forward direction of motion of the traction vehicle suchthat each cutting unit rolls from side-to-side in response to lateralchanges in ground contour.